Enclosures such as storage sheds are a necessity for lawn and garden care, as well as general all-around home storage space. Typically, garden tools and equipment are found either stacked into a corner of the garage, or bundled together and covered with a tarpaulin to protect them from the elements. During the off-seasons, lawn mowers, tillers and snow equipment often consume the available floor space of a garage, forcing the homeowner to park his automobile outside.
The prior art has proposed a number of different panel systems, or kits comprising blow molded or extruded panels and connector members for forming a wide variety of structures. Due to manufacturing limitations blow molded and extruded plastic components cannot be formed with the integral cross-bracing ribs or the intricate shapes and sharp corners required for integrated connectors that are possible with injection molding. Typically, such systems require extruded metal or plastic connector members having a specific cross-sectional geometry that facilitate an engagement between such members and one or more plastic panels having a complimentary edge configuration.
A particularly common structure for the connector members is the I-beam cross section. The I-beam defines free edge portions of the connector member which fit within appropriately dimensioned and located slots in the panel members. U.S. Pat. No. D-371,208 teaches a corner extrusion for a building sidewall that is representative of the state of the art I-beam connector members. The I-beam sides of the connector engage with the peripheral edge channels of a respective wall panel and thereby serve to join such panels together at right angles. Straight or in-line versions of the connector members are also included in the kits to join panels in a coplanar relationship to create walls of varying length.
Extruded components generally require hollow longitudinal conduits for connection and strength. Due to the nature of the manufacturing process the conduits are difficult to extrude in sections long enough for structural panels. Thus, they require connectors to achieve adequate height for utility shed walls. A common structure for connecting extruded members has a center I-beam with upper and lower protrusions for engaging the conduits. However, wall panels utilizing I-beam connectors are vulnerable to buckling under loads and may have an aesthetically unpleasing appearance. Moreover, roof loads from snow and the like may cause such walls to bow outwardly due to the clearances required between the connectors and the internal bores of the conduits. U.S. Pat. No. 6,250,022 discloses an extendable shed utilizing side wall connector members representing the state of the art. The connectors have a center strip with hollow protrusions extending from its upper and lower surfaces along its length. The protrusions are situated to slidably engage the conduits located in the side panel sections to create the height needed for utility shed walls.
The aforementioned systems can also incorporate roof and floor panels to form a freestanding enclosed structure such as a utility shed. U.S. Pat. Nos. 3,866,381; 5,036,634; and 4,557,091 disclose various systems having inter-fitting panel and connector components. Such prior art systems, while working well, have not met all of the needs of consumers to provide structural integrity combined with modularity and aesthetic appearance. Paramount among such needs is a panel system which eliminates the need for I-beam connectors creating enclosure walls which resist panel separation, buckling, racking and weather infiltration. It is also desirable for the wall formed by the panels to tie into the roof and floor in such a way as to unify the entire enclosure. Also, from a structural standpoint, a door must be present which can be easily installed after assembly of the wall and roof components, is compatible with the sidewalls, and provides dependable pivoting door access to the enclosure. All known prior art requires the roof to be partially disassembled before the doors can be installed.
There are also commercial considerations that must be satisfied by any viable enclosure system or kit; considerations which are not entirely satisfied by state of the art products. The enclosure must be formed of relatively few component parts that are inexpensive to manufacture by conventional techniques. The enclosure must also be capable of being packaged and shipped in a knocked-down state. In addition, the system must be modular and facilitate the creation of a family of enclosures that vary in size but share common, interchangeable components.
Finally, there are ergonomic needs that an enclosure system must satisfy in order to achieve acceptance by the end user. The system must be easily and quickly assembled using minimal hardware and requiring a minimal number of tools. Further, the system must not require excessive strength to assemble or include heavy component parts. Moreover, the system must assemble together in such a way so as not to detract from the internal storage volume of the resulting enclosure or otherwise detract from the internal storage volume of the resulting enclosure or otherwise negatively affect the utility of the structure.